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EP0768777A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method and apparatus for restoration of an ATM network

Assignee: AT&T Inc
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Filing: 1996-10-01
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Granted: —
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Expires: 2016-10-01
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Abstract

Abstract The present invention is a restoration scheme for an ad-hoc ATM LAN wherein ATM cells are transported over a wireless point-to-point link. A method for restoring communications in the ATM network includes the steps of: generating a failure message indicative of a failure of a network element, the failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; communicating the failure message to all said switching nodes in said network; and referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network. Each of the switching nodes is included in a network tree spanning all said switching nodes in the network, wherein each of the switching nodes is included as a root in a specific network tree, each said network tree having a tree identification, the failure message further including a tree identification field containing the tree identification. The method also includes the step of routing the failure message in the switching nodes of the network based on the tree identification. The failure message includes a time stamp indicative of the time said failure message was generated, and the referencing of the updated routing tables is delayed a predetermined time period from the time of said time stamp before referencing said updated routing tables.

Inventors

  • 👤 Ender Ayanoglu
  • 👤 Kai Yin Eng

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 20:56
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/12; H04L1/16; H04L1/1607; H04L1/1671; H04L1/1678; H04L45/00; H04L45/02; H04L45/28; H04L45/48; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04L1/004; H04L1/0056; H04L1/0057; H04L1/1614; H04L1/18; H04L1/1812; H04L1/1867; H04L1/187; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5603; H04L2012/5604; H04L2012/5607; H04L2012/5614; H04L2012/5619; H04L2012/5625; H04L2012/5627; H04L45/484; H04W; H04W8/00; H04W8/26; H04W84/00; H04W84/02; H04W84/10; H04W84/12; H04W84/18

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 108 words
A method of restoring communications in an ATM network, said network including a plurality of network elements including network links and network switching nodes, said network switching nodes adapted for communications with wireless mobile devices, said method comprising the steps of: generating a failure message indicative of a failure of a network element, said failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; communicating said failure message to all said switching nodes in said network; and referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network.
Claim 2
Independent Claim 108 words
A method of restoring communications in an ATM network, said network including a plurality of network elements including network links and network switching nodes, said network switching nodes adapted for communications with wireless mobile devices, said method comprising the steps of: generating a failure message indicative of a failure of a network element, said failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; communicating said failure message to all said switching nodes in said network; and referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network.
Claim 3
Dependent Claim 85 words
The method of Claim 1, wherein each of said switching nodes is included in a network tree spanning all said switching nodes in said network, wherein each of said switching nodes is included as a root in a specific network tree, each said network tree having a tree identification, said failure message further including a tree identification field containing said tree identification, said method further including the step of: routing said failure message in said switching nodes of said network based on said tree identification.
Claim 4
Dependent Claim 45 words
The method of Claim 1, wherein said failure message includes a time stamp indicative of the time said failure message was generated, further including the step of: delaying a predetermined time period from the time of said time stamp before referencing said updated routing tables.
Claim 5
Dependent Claim 30 words
The method of Claim 3, wherein said predetermined time period is selected to enable said failure message to propagate to all said switching nodes in said network under loaded conditions.
Claim 6
Dependent Claim 30 words
The method of Claim 1, further including the step of calculating said updated routing table at said network switching nodes using a routing algorithm prior to said step of referencing.
Claim 7
Dependent Claim 29 words
The method of Claim 1, wherein an updated routing table for each said failure identification is calculated at a time of network generation and prestored in said switching nodes.
Claim 8
Dependent Claim 38 words
The method of Claim 1, wherein said updated routing tables are calculated by an agent for a group of said switching nodes, said updated routing tables being propagated to said group of switching nodes via a signaling channel.
Claim 9
Independent Claim 46 words
The method of Clam 1, wherein said network utilizes destination routing for messages propagated therein, wherein VPI/VCI destination addresses are included in a header of said message, wherein routing of said messages is based on a routing table in said switching nodes including said destination address.
Claim 10
Independent Claim 46 words
The method of Clam 1, wherein said network utilizes destination routing for messages propagated therein, wherein VPI/VCI destination addresses are included in a header of said message, wherein routing of said messages is based on a routing table in said switching nodes including said destination address.
Claim 11
Dependent Claim 83 words
The method of Claim 1, further including the step of determining whether a message received at said switching nodes is a failure message, said step of determining including the steps of: storing an incoming message in a buffer of said switching nodes; performing a modulo-2 summation between each bit of a header portion of said incoming message and said predetermined VPI/VCI reserved for failure reporting; and checking said summation for all zero values, wherein all zero values indicate receipt of said failure message.
Claim 12
Dependent Claim 19 words
The method of Claim 1, wherein said failure message is generated from a receiving one of said switching nodes.
Claim 13
Independent Claim 151 words
A system for restoring communications in an ATM network, said network including a plurality of network elements including network links and network switching nodes, said network switching nodes adapted for communications with wireless mobile devices, said network utilizing destination routing for messages propagated therein, wherein VPI/VCI destination addresses are included in a header of said message, wherein routing of said messages is based on a routing table in said switching nodes including said destination address, said system comprising: means for generating a failure message indicative of a failure of a network element, said failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; means for communicating said failure message to all said switching nodes in said network; and means for referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network.
Claim 14
Independent Claim 151 words
A system for restoring communications in an ATM network, said network including a plurality of network elements including network links and network switching nodes, said network switching nodes adapted for communications with wireless mobile devices, said network utilizing destination routing for messages propagated therein, wherein VPI/VCI destination addresses are included in a header of said message, wherein routing of said messages is based on a routing table in said switching nodes including said destination address, said system comprising: means for generating a failure message indicative of a failure of a network element, said failure message including an identification of said network element and a predetermined VPI/VCI reserved for failure reporting; means for communicating said failure message to all said switching nodes in said network; and means for referencing updated routing tables at said switching nodes, wherein said network element indicated in said failure message is eliminated from routes in said network.
Claim 15
Dependent Claim 84 words
The system of Claim 12, wherein each of said switching nodes is included in a network tree spanning all said switching nodes in said network, wherein each of said switching nodes is included as a root in a specific network tree, each said network tree having a tree identification, said failure message further including: a tree identification field containing said tree identification, said system further including: means for routing said failure message in said switching nodes of said network based on said tree identification.
Claim 16
Dependent Claim 48 words
The system of Claim 12, wherein said failure message includes a time stamp indicative of the time said failure message was generated, said network nodes further including: means operable to delay a predetermined time period from the time of said time stamp before referencing said updated routing tables.
Claim 17
Dependent Claim 29 words
The system of Claim 12, further including means for calculating said updated routing table at said network switching nodes using a routing algorithm prior to said step of referencing.
Claim 18
Dependent Claim 29 words
The system of Claim 12, wherein an updated routing table for each said failure identification is calculated at a time of network generation and prestored in said switching nodes.
Claim 19
Dependent Claim 39 words
The system of Claim 12, further including a network agent for calculating said updated routing tables for a group of said switching nodes, said updated routing tables being propagated to said group of switching nodes via a signaling channel.
Claim 20
Dependent Claim 84 words
The system of Claim 12, further including means for determining whether a message received at said switching nodes is a failure message, said means for determining including: buffer means for storing an incoming message in said switching nodes; computing means for performing a modulo-2 summation between each bit of a header portion of said incoming message and said predetermined VPI/VCI reserved for failure reporting; and means for checking said summation for all zero values, wherein all zero values indicate receipt of said failure message.
Claim 21
Dependent Claim 30 words
The system of Claim 14, wherein said predetermined time period is selected to enable said failure message to propagate to all said switching nodes in said network under loaded conditions
Claim 22
Dependent Claim 19 words
The method of Claim 5, wherein said routing algorithm is selected from the group consisting of Dijksta and Bellman-Ford.

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